Here's what is written in your task description, in the announcement

yes and here's also what is written in it:

Who can participate: only those who secured 🥈2nd or 🥉3rd places in Round 1.

and on top of it, it's a design contest, not "submit your idea in text as a comment" :)

At the same time, the suggestion portal appears to be largely inactive, and the voting system does not seem to have much practical impact anymore. In my experience, it mostly generates notification spam rather than meaningful feedback.

that's as far from truth as it can only be, the portal is very much alive and has higher chance of suggestion getting through than posting it on an unrelated group as a comment to a contest announcement.

on top of it all, the platform is not a democracy voting system that requires lots of votes, a good idea can defend itself. votes are only a measurement system.

but either way, this group is for discussing competitions organized by Telegram, it's not for sending suggestions, as i said in my initial message